The GCSPOPCX characteristics are:
Loads an exception return record from the location indicated by the current Guarded Control Stack Pointer register, compares the values loaded with the current ELR_ELx, SPSR_ELx, and LR, and increments the current Guarded Control Stack Pointer register by the size of a Guarded Control Stack exception return record.
This instruction is present only when FEAT_GCS is implemented and FEAT_AA64 is implemented. Otherwise, direct accesses to GCSPOPCX are UNDEFINED.
GCSPOPCX is a 64-bit System instruction.
This instruction has no applicable fields.
The value in the register specified by <Xt> is ignored.
Rt should be encoded as 0b11111. If the Rt field is not set to 0b11111, it is CONSTRAINED UNPREDICTABLE whether:
The instruction is UNDEFINED.
The instruction behaves as if the Rt field is set to 0b11111.
Accesses to this instruction use the following encodings in the System instruction encoding space:
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b01 | 0b000 | 0b0111 | 0b0111 | 0b101 |
if !(IsFeatureImplemented(FEAT_GCS) && IsFeatureImplemented(FEAT_AA64)) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if IsFeatureImplemented(FEAT_GCS) && GetCurrentEXLOCKEN() && !Halted() && PSTATE.EXLOCK == '1' then EXLOCKException(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGITR_EL2.nGCSEPP == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif GCSEnabled(EL1) then GCSPOPCX(); elsif PSTATE.EL == EL2 then if IsFeatureImplemented(FEAT_GCS) && GetCurrentEXLOCKEN() && !Halted() && PSTATE.EXLOCK == '1' then EXLOCKException(); elsif GCSEnabled(EL2) then GCSPOPCX(); elsif PSTATE.EL == EL3 then if IsFeatureImplemented(FEAT_GCS) && GetCurrentEXLOCKEN() && !Halted() && PSTATE.EXLOCK == '1' then EXLOCKException(); elsif GCSEnabled(EL3) then GCSPOPCX();
21/03/2025 17:52; 154105dd5041532b480d9ef0c018b8420cbe5c19
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